Hi all,

I have an automatic 04 xtype with ~100k miles on it. I have a couple questions about some behavior I've noticed from the car, and I'm hoping the community can help narrow it down so I can take it to a shop with a better idea of what to tell them.

I've noticed two things:

1. Noticeably anemic acceleration from standstill, and large hesitation when pressing the accelerator while in motion. I swear a moped would beat my car off the block right now. I try to baby it when accelerating from a standstill, but the traffic patterns in the 'burgh necessitate some...active driving at times. In most, if not all, cases the car feels very sluggish off the block. I can't pinpoint when I started noticing this exactly; I think it's been a slowly developing thing. I have no lights on the dash, and haven't noticed any particular noises or other oddities that might indicate what's up. Possibly a stupid question, but is there any chance the rear diff is dead/bad? Would the car even run without it?

2. Between ~30 and ~50 mph, the car will drop into 4th gear (I think) too soon, especially when not constantly accelerating. It's very clear when it does this, as there will be a noticeable drop in tone from the drivetrain and the gas pedal will feel "dead". When in this situation, trying to accelerate in any way other than stomping on the gas will result in either extremely anemic acceleration or (more commonly) the transmission slipping over and over until I mash the gas or slow to the point where it downshifts.

Some time ago I did get a "Gearbox Fault" indicator, however I also needed to replace the battery and, after doing so, the "Gearbox Fault" light went away and did not re-light. The car performed similarly (i.e. like I described above) both before and after this. I have noticed that "Sport" mode lessens the severity of the problem, however it does not eliminate it entirely.

Some additional background, I had the transmission fluid flushed & replaced, as well as the fluid in the TC and rear diff drained & replaced at ~80k miles. The TC looks to have been replaced at some point before I took ownership of the car, although this is just a guess based on the fact that it has what look to be junkyard numbers on it. Unfortunately the records I received when I bought the car didn't indicate this anywhere, so I may be wrong.

I'd really love to be able to narrow down what might be going on here, so any help will be much appreciated. I'd be happy to re-state or elaborate on anything I've written as well.

Thanks!

 

jjbuck2, from what you are describing, this is sounding like a vacuum leak or oil in the cylinder. Granted, I would anticipate it causing a code to help narrow things down a little bit.

As for figuring out the problem, the first thing would be to get your hands on a vacuum gauge or a code reader that can tell you the intake vacuum. At idle and the car in PARK, you should be seeing around 25" of vacuum. If you are down around 20" or even less, then you have a vacuum leak. This is where checking the big 3 (PCV hose, brake booster hose, IMT o-rings) is where I would start and then take things from there.

If you are feeling adventurous, you can check the plug wells for oil. Normally the #1 and #3 wells are the main culprits. Unfortunately, you have to pull the top of the intake off as these are the back wells (#1 is on the passenger side of the engine, #3 is the center well, both on the back side of the engine). When you pull the coil off of the plug, look at the end of the rubber boot. If you see oil there, that would be a sign that you have 2 plugs that are more than likely not firing at full potential, effectively making your car run like it is a 4 cylinder. Granted, may not be a bad idea to think about a plug change as it is due on the car at 100K miles and unless you know when it was last done, I would assume that it hasn't be done yet and this can also affect the performance if the gap of the spark plugs has gotten too big.

 

The transmission "learns" based on the driving style used over time. If you have been pretty much babying the car when you drive it all this time the shifting will be a lot more "relaxed". If you accelerate aggressively most of the time over a long period the shifts will reflect that too. So, maybe all you need is to rest the transmission and start over with the base settings from the factory and let it relearn. I can't specifically remember how to do that. I think it involves disconnecting the battery and touching the cables together. I'm sure with a quick search on here you can find that or someone will chime in.

 

First and easiest thing is replace fuel filter see if it get any better? If not do as Thermo said.

 

 

jjbuck2, one other check that you can do is to find a back, country road and do a long, hard acceleration. What t his will do is to push the limits of the car and if there is a problem, will make the check engine light come on. At that point, looking at the code will help point you in a direction.

 

Thanks for the responses everyone!

I've had changing the fuel filter on my mind for quite a while now and have never gotten around to it. I'll do that as soon as I have a chance and see if it makes a difference.

Thermo, I have an ODBII reader...do you think that would that give me the info I need to check the intake vacuum? I think it displays that info but I've never actually used it for that purpose.

Also, are the IMT o-rings the ones on the ends of the manifold? If so, I've replaced the original sickly-yellow ones with more robust versions. This was about a year and a half ago.

I might try Alfadude's suggestion as well. I'm sure I can find a guide for resetting the TCM, but if anyone has any tips I'd appreciate them.

Finally, Thermo again, I'll see if I can take it out this week and do a hard burn. If I get any results from that I'll let you know.

Thanks again everyone, I really appreciate it.

 

jjbuck, whether your OBD reader has that feature is hard to say. Some do, some don't. Give it a try and see what you end up with. As for the IMT o-rings, yes, those are the ones on the end of the intake manifold (nearest the passenger front wheel on your car). If you have recently changed them, then those should be good. If you want to check them, let me know.

When it comes to resetting the TCM, just disconnect the battery for a minute or so and then reconnect. That will reset all the computers and get you back to square 1. Just don't forget that you will need to reset your windows. But that is easy. If you need to know how, let me know.